write an automatic workflow software in Java Spring MVC

Hi I need to implement a workflow in Java Spring MVC for my sales marketing. Need to have eBay developer account. You can apply for this very easily. And there is a sandbox in ebay for you to conduct testing. The implementation also need to login Paypal account to send invoice to customers based on eBay customers. Basically the workflow is like this: 1. retrieve all "sold records" from ebay by dates range (based on sold date) 2. based on these sold records, write all records which are already paid to a file; and then write all sold records which are not yet paid to another file. 3. based on the not-yet-paid records, manually update this file with postage for each record, and then the program retrieve each pair of the record -> login Paypal automatically and create invoice based on the email address, and then add item name / description and postage for the invoice, 4. send paypal invoice . I am able to offer $300 for this work.